America's most notorious pornographer yesterday accused one of the prosecutors in President Clinton's Senate trial of condoning his ex-wife's abortion and then lying about it.

Larry Flynt's allegation defied Washington's efforts to drag the impeachment saga from a quagmire of scandal.

Bob Barr, a rightwing Republican congressman from Georgia and one of the prosecution "managers", denied the allegations, adding: "I have steadfastly worked to focus attention on substantive issues like perjury and obstruction of justice, and away from lurid personal allegations."

Mr Flynt accused him of hypocrisy. At a Beverly Hills press conference, the publisher of Hustler magazine produced an affidavit signed by Gail Barr, the congressman's ex-wife.

She claimed he had condoned and paid $300 for an abortion in 1983. She also claimed that he drove her to the clinic and looked after their two children while the operation was performed.

Mr Flynt contrasted this with Mr Barr's statement at the couple's divorce proceedings three years later, when he said under oath that he had opposed the abortion. In her statement, Ms Barr also accused Mr Barr of having an affair with Jerilyn Dobbin while he was still married to Ms Barr. Mr Barr married Ms Dobbin a month after the divorce. At the divorce hearings, he refused to answer questions about his alleged adultery.

"I just want to expose him for what he is," Mr Flynt said, warning of eight more exposés; of leading figures.

The porn magnate has been a major player in the political scene since he bought a full-page advertisement in the press in October offering $1 million to anyone who had "had an adulterous sexual encounter with a current member of the United States Congress or a high-ranking government official".

Hustler magazine said the response was overwhelming. The resignation in December of Bob Livingston as Republican leader is thought to have been triggered by Hustler's activities.

The publisher, living up to his 1996 Hollywood portrayal in The People vs Larry Flynt as a scourge of society's double standards, said his aim was to expose hypocrisy in the impeachment process.

He said: "There is nothing that will change someone's moral outlook quicker than cash in large sums."